Embodiments disclosed herein relate to an operation method of a memory device, and more particularly, to a method of repairing a plurality of word lines by using redundant word lines and devices using the same.
In general, when a defect occurs in a memory cell, a semiconductor chip is equipped with a redundant memory block to replace the memory cell.
When a memory access operation is performed on a defective cell where a defect occurs, the defective cell may be repaired by being replaced with a redundant memory cell included in a redundant memory block.
When a normal word line includes a defective cell, all of the normal word line may be replaced with a redundant word line included in the redundant memory block. In this case, a normal word line may be repaired with a redundant word line and normal memory cells included in the normal word line may not be used, thereby lowering efficiency of repair.